"There is a process," Byrd-Bennett said of the potential school closings after being introduced by Mayor Rahm Emanuel on Friday. "Everything must be on the table. As we've said, we face huge academic and huge financial issues in our district. This is about matching seats to the number of children we have. It's about putting every piece of information we have on the table."

Emanuel's first pick to run the city's troubled school system, Jean-Claude Brizard, lasted 17 months before realizing he was out of favor and "becoming a distraction" in the mayor's push to overhaul schools.

Brizard was in Emanuel's doghouse for some time and had been told by this past summer that the mayor would blame him for the deadlocked contract talks with the Chicago Teachers Union that led to a seven-day strike. Among other miscues, Brizard took a vacation as heated negotiations dragged on.

"This guy was the head of the school system," said Ald. Patrick O'Connor, 40th. "People expect you to be at a post at a time like that, and he wasn't.

"You pick people and hope that it's going to work out, and when it doesn't, I think you have to have the leadership to say this isn't working and change course," said O'Connor, defending the mayor's move.

Brizard will get a full year's salary as part of his severance package, district officials said Friday. The school board gave Brizard a two-year contract at $250,000 a year when it hired him in April 2011. The contract was to expire in May.

Byrd-Bennett declined to give details on how she will approach school closings — sources have told the Tribune the city is considering closing 80 to 120 underperforming and underenrolled schools, most of them in African-American neighborhoods that have lost significant population in the last decade. The closings are expected to be fiercely contested by community leaders as well as the teachers union.

"It's also about community trust and respect. So there's a process. There is no plan," she said. "I continue to hear a plan and a number, and it makes me smile because there is no plan, there is no number. But everything is being considered in consultation with the board and fact-gathering and the mayor."

Emanuel on Wednesday told the Tribune editorial board that the schools have slots for 600,000 children when there are 405,000 attending, although he did not say how many schools would be closed or converted to privately run charter schools, even as he conceded the difficulty of closing schools.

"It's a very difficult process," he said. "Folks, this is hard, I got it. People get attached. And (I) understand it. But we've got to make sure we can give the kids the education."

The mayor said Friday that Brizard approached Chicago Board of Education President David Vitale about stepping down because questions about how long he would last in the post had become a distraction. Brizard offered a similar account of the events leading to his departure Thursday night.

Emanuel said Byrd-Bennett, 62, previously the district's interim chief education officer, is the right person to move the system forward.

Emanuel said the teachers contract, which still needs to be approved by the school board, presents opportunities for moving forward and that "the questions and distractions around Brizard were taking away from the mission."

"And (Brizard) was totally professional about it in coming forward and saying this is not going to work for what we have to do, and I don't want to be the stumbling block or the distraction from achieving what we need to achieve for the kids," Emanuel said.

While the teachers contract will bring at least a few years of labor peace, Byrd-Bennett still faces significant challenges. In addition to the potential school closings, the district is forecasting an estimated $1 billion deficit in the coming year, having emptied its cash reserves to address a $665 million deficit this year.

Byrd-Bennett said Friday that she called CTU President Karen Lewis on Thursday night and had a "very, incredibly productive conversation."

"I'm looking forward to two things: a collaborative and productive relationship with Karen and the members of the CTU, as well as the rank-and-file teachers," Byrd-Bennett said.

Emanuel called Byrd-Bennett's strong working relationship with Lewis "an aspect" of why he thinks she will be successful as CPS considers closing schools.

Ald. Joe Moore, 49th, suggested Brizard may have been in trouble from the start because he was perceived as "anti-union and somewhat dictatorial in his management style. That's not a good basis to start out a new job, particularly when there are already tensions and difficult decisions that have to be made."

Byrd-Bennett, by contrast, appears to have the respect of the unions, Moore said.

"At least they start out from a place of mutual respect, which in my opinion goes a long way, and I don't think they ever had the respect for Brizard," he said.

Byrd-Bennett's performance during the strike showed she could take the heat, he added.

"I think that the observations of her under the pressure of the strike are in part what has shaped her as being the choice," O'Connor said. "I think that they feel that she was helpful and on task and in command of the issues. I just think that there is some confidence there, and that's why this person is the pick."